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Finding the Fourth Proportional to 621.18, 856.86 and 397.08

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Solution

The fourth proportional to 621.18, 856.86 and 397.08 is: 547.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.18 : 856.86 = 397.08 : x
  2. Step 2: Convert to fraction form
    621.18/856.86 = 397.08/x
  3. Step 3: Cross multiply
    621.18x = 856.86 × 397.08
  4. Step 4: Simplify right side
    621.18x = 340,241.97
  5. Step 5: Solve for x
    x = 340,241.97/621.18
  6. Step 6: Final answer
    x = 547.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.